The nature of complexity facing novice designers in a constraint satisfaction task.

This paper examines the effects of different types of complexity facing novice designers in constraint satisfaction tasks. The nature of the complexity in a design task was varied by manipulating different aspects of the extrinsic constraints, which refer to restrictions concerning how design components can be assembled. We investigated the effect of the number of constraints (Study 1) and the number of different types of constraint (Study 2) in a simulated office design task. Results indicated that tackling a design task with a greater number of constraints, or more types of constraint, resulted in decrements in performance. Study 3 examined the effect of reasoning about constraints that involved a fixed location in the office layout and those that did not. It was found that having a higher proportion of constraints that referenced a fixed location led to better design performance. The theoretical and practical aspects of these results are discussed. Practitioner summary: This paper identifies sources of constraint complexity facing the novice designer in an office design task. Three features of constraints proved problematic: the number of constraints, the number of types of constraint and whether the constraint involved a specific location. Training and decision support solutions are discussed.